Tornado cuts power to Surry nuclear power plant
- April 18, 2011
The weekend storm that spawned deadly tornados over some parts of North Carolina and Virginia knocked out electrical power to two nuclear units at Dominion Virginia Power’s Surry Power Station. The U.S. Nuclear Regulatory Commission said Monday that it’s monitoring the situation after Surry’s offsite power was knocked out early Saturday evening by a tornado.
According to Dominion Virginia Power, an apparent tornado touched down on the switchyard supporting the power station near the facility’s access road, cutting off the electrical feed from the grid to the station. The plant is located about 17 miles northwest of Newport News.
The NCR reported that Surry’s two units automatically shut down after losing power, and four of the plant’s diesel generators started to power the units’ emergency loads. Dominion notified the NRC of the situation soon after it happened and declared an “unusual event,” the lowest of the four NRC emergency classification levels, around 7 p.m.
Roger Hannah, a spokesman for the NRC in Atlanta, said the agency sent its two resident inspectors to Surry, and also is following the situation through an incident response center in Atlanta. “In a situation like this, we have a handful of technical experts on standby in Atlanta, so the resident inspectors can call and ask questions.” He said the NRC assigns resident inspectors to every U.S. nuclear plant, and that the typical number, as in the case with Surry, is two. Monitoring will continue, Hannah added, until “they restore the offsite power, and I think they are well on the way to doing that … When they say they are no longer in the unusual event, we’ll stop the monitoring, although we may do a follow up inspection.”
By early afternoon today, Dominion Virginia Power said crews had restored power, although the NRC was reporting that power had been partially restored.
Dominion said in a press release that the tornado did not strike the two nuclear units, which are designed to withstand natural events such as tornados, hurricanes and earthquakes. The reactors are housed inside steel reinforced concrete containment buildings. In addition, the company reported no release of radioactive material beyond minor releases associated with normal station operations. Dominion said these minor releases are below federally approved operating limits, and pose no threat to station workers or the public.
There were no injuries at the site. In addition to the NRC, Dominion notified state and local officials about the power outage.
Asked about the frequency of tornados knocking out power to nuclear plants in this country, Hannah said it’s not unheard of during bad storms. “I don’t know of any that have completely lost offsite power, but it’s not unusual with bad storms to lose power. It’s unusual to have a switchyard problem, where you lose all power, but it’s not unheard of.”